The Department of Transportation spokesman said the tests are "another example of our continuing efforts to further assess the state of our aviation system that we inherited from the private sector. We're trying to make it better."

Asked if passengers should be worried in the months before federal screeners are in place, Alcivar said, "They should know we're not ever satisfied with the level of aviation security. Passengers should be assured about that."

He added, "Our airports are safer," pointing to an increase in the number of bags screened, the fact that bags are now matched with their owners on flights and that cockpit doors have been strengthened.

Alcivar says the tests were ordered by Transportation Secretary Norman Y. Mineta and were conducted to provide a benchmark against which the TSA will conduct future tests.

"We've known there were problems with the system. That's why TSA was created," said Alcivar. "We'll do more of these."

John Simonetti, a federal screener, works at the Louisville, Kentucky, airport.

Some of the new federal security screeners will be hired from the private security screening companies. Alcivar said, "We will weed out those who underperform."

Federal screeners are now at just three airports -- in Baltimore, Maryland; Louisville, Kentucky; and Mobile, Alabama.

Plans call for them to be in place at all 429 commercial airports by November 19 -- Alcivar said they will be more highly trained.

They'll have "five times the amount of training", be subjected to continuous undercover testing and have to pass rigorous tests.

"We'll have higher standards. As we move to a system with federal security screeners we're going to insists on dramatic improvements in security. We're going to see them," he said.